Many applications today rely on location information of users or devices, yet disclosing such information without appropriate measures presents heightened privacy and safety threats. Currently there is no technique which can effectively prevent one from being identified and located should one's detailed movement be tracked. This lack of protection has greatly hindered the development and deployment of a wide range of important applications like location-based services. There is an urgent need, therefore, to develop techniques that allow users or devices to disclose their location information as accurately as possible for useful applications while providing them location privacy protection, i.e., ensuring such information cannot be used by adversaries to derive who is where at what time.
In addition, there are problems relating to a user's ability to specify a desired level of privacy protection in a meaningful way. What is needed is a convenient and effective way for users to specify their desired level of privacy protection.